GPU choice A100, H100 or L40S

[jinyangguo]

Dear developer and user,

Our group is going to purchase a server with GPUs. Are there any test examples running on different GPUs for comparison and recommendation? Like A100, H100, and L40S, we would like to know about the accumulating ability of these GPUs. We mainly calculate median size models normally (100-300 atoms).

Thanks,
Nick

[michael_wolloch]

Dear Nick,

the VASP company cannot recommend specific hardware solutions, only provide some general points to consider:

1) While the openACC port of VASP can run in principle on any NVIDIA GPU, FP64 performance is key. This makes "consumer hardware" cards (with RTX and Titan branding) unreasonable due to the typically 1:64 performance drop from FP32 to FP64, which is only 1:2 for "data center" cards like the A30 or A100.

2) GPU memory size is important. You have to fit the wavefunctions on the device entirely. Double your typical WAVECAR size (it is printed in single precision I think) to estimate minimum memory requirements. The number of atoms alone is not enough to judge memory impact.

3) Not all capabilities of VASP are available in the GPU port as of now. For example, everything using RPA is not enabled currently, which includes GW calculations. On the other hand, hybrid functionals, for instance, scale especially well on GPUs.

There are some benchmarks from NVIDIA concerning multi-node scaling and energy efficiency available, although they are a bit outdated in parts:

https://developer.nvidia.com/blog/scali ... magnum-io/
https://developer.nvidia.com/blog/optim ... magnum-io/

[jinyangguo]

Hi,

Thanks a lot, Michael. The information you provide is quite helpful.
Yes, I saw some examples with A100, but few with H100 and L40S.

Best